1. Field of the Invention
The present invention relates to an information terminal apparatus with the liquid crystal display. More particularly, it relates to an information processing apparatus that is suitable for using face-to-face.
2. Description of the Prior Art
In an information processing apparatus such as a personal computer, as the display apparatus, there is used in many cases a liquid crystal display apparatus that is easy to downsize in the aspects of weight and outside appearance in comparison with the other types of display apparatuses. Such liquid crystal display apparatuses contain a built-in back-light and utilize its light as the light source, thereby implementing an enhancement of the visibility.
Basically speaking, one person has used the above-described information processing apparatus so far. In recent years, however, there has been appearing the usage style that two persons communicate in a state where they are face-to-face with each other. One example is a usage style that, when a business staff wishes to utilize a picture on the screen of the information processing apparatus for the presentation toward a client, the business staff and the client see the picture in the state of being face-to-face with each other. In that case, if a display direction of the picture in which a user normally looks at the picture is assumed to be 0xc2x0 as is illustrated in FIG. 1A, a state where the display direction of the picture is inverted by the amount of 180xc2x0 (FIG. 1B), i.e., the display direction of the picture is changed into the facing direction, allows the facing person to find it easier to see the picture.
However, in the liquid crystal display apparatuses used widely in general, there exists an optimum viewing angle. This condition results in a characteristic that, depending on the seeing angle, a contrast of the displayed content differs outstandingly. As a consequence of this characteristic, the ease with which the displayed picture can be seen has differed exceedingly, depending on the seeing angle or the seeing position toward the displayed picture.
As a solving method for this problem, JP-A-7-146461 has proposed and disclosed the following method: At the time of changing the display direction of the picture, a field-of-view angle setting voltage is switched and controlled so as to adjust the field-of-view angle, thereby making it easier to see the picture from the facing side as well.
Also, in a battery-driven portable type information processing apparatus, a power consumption by the display apparatus occupies a tremendous percentage out of a power consumption of the battery. In view of this situation, in many cases, a luminance of the display apparatus is set in advance to be a necessary minimum amount in order to reduce the power consumption. Moreover, in some information processing apparatus, there is performed a control that, depending on the operation state, sets a working condition of the display apparatus to be a power saving state.
The above-described method disclosed in JP-A-7-146461, however, necessitates a circuit for the field-of-view angle setting voltage that is not provided in the commonly used liquid crystal display apparatuses. This has made the liquid crystal display apparatuses special, becoming an obstacle against the provision of inexpensive liquid crystal display apparatuses.
Also, in the conventional information processing apparatus, there has existed the following problem: On account of the power saving control over the liquid crystal display apparatus or the information processing apparatus, the luminance of the liquid crystal display apparatus is varied or extinguished even when the display apparatus is used in the state where the display direction of the picture has been inverted by the amount of 180xc2x0 in the use for the presentation and so on.
It is an object of the present invention to provide, at a low price, a display controlling apparatus that allows the facing person to find it easier to see the picture without the necessity of an additional circuit such as the above-described circuit for the field-of-view angle setting voltage.
Furthermore, it is another object of the present invention to provide a display controlling apparatus that sets an optimum working condition automatically between the normal usage state and the state where the display direction of the picture has been inverted by the amount of 180xc2x0. Namely, when, normally, one person uses the information processing terminal, he or she takes the driving time into consideration. Accordingly, in many cases, the one person sets the luminance of the liquid crystal display apparatus to be the necessary minimum amount, the power consumption by the liquid crystal display apparatus occupying the great deal of percentage out of the power consumption of the battery in the information processing terminal. When changing the picture direction in this state, since the luminance remains unchanged, the following operation becomes required: Especially when utilizing the picture for the presentation and so on and in changing the picture direction (by the amount of 180xc2x0) in order to show the picture to the person on the facing side, it becomes required to take the following operation into consideration: Increasing the luminance as high as possible to make the picture easy to see and to make a favorable impression on the facing person, and the like. However, a picture direction change instructing member and a luminance adjusting member are usually operated independently of each other. This condition requires an operator to adjust the luminance manually after changing the picture direction, thereby making the operation complicated. Also, in this case, when restoring the picture direction back to the original picture direction, the luminance that has been set at the time of inverting the picture direction (by the amount of 180xc2x0) continues to exist without being altered. This situation requires the operator to reset the luminance back to the original luminance at the time of the operation of restoring the picture direction back to the original one. In addition, if the operator should miss the resetting operation, the display apparatus will work still remaining in the higher luminance state against the operator, original intention. This situation increases the power consumption, eventually resulting in shortening the driving time of the battery.
In the present invention, in order to solve the above-described problem, a displayed picture upside-down inversion controlling member and the luminance adjusting member are caused to be operated in being coupled with each other so that, when the picture direction change instructing member instructs the displayed picture upside-down inversion controlling member to invert the display direction of the picture into the 180xc2x0-direction, the luminance of the display apparatus is caused to be automatically adjusted in such a manner as to be coupled together with the upside-down inversion of the displayed picture. This automatic adjustment, at the time of the inverted display, increases a light amount from the picture on the liquid crystal display apparatus, thus increasing a light amount toward the field-of-view in an oblique direction. As a result, the visual recognizablity becomes improved from the facing side as well, thereby being capable of making the field-of-view look enlarged than it really is.
Also, in order to solve the above-described another problem, there is provided a storing member for latching the set luminance value of the displayed picture, thereby storing the set luminance value of the displayed picture before being inverted by the amount of 180xc2x0. Thus, when restoring the displayed picture back to the normal usage state (i.e., 0xc2x0-direction), the luminance of the displayed picture is restored and reset by referring to the value stored in the storing member for latching the set luminance value.
Also, in order to solve the above-described still another problem, the displayed picture upside-down inversion controlling member, the luminance adjusting member and a power saving controlling unit are caused to be operated in being coupled with each other. As a consequence, when inverting the displayed picture by the amount of 180xc2x0, the operation of the power saving controlling unit is prohibited from lowering at least the picture luminance (the power saving controlling unit is caused to be operated in such a manner that it will not lower at least the picture luminance). Moreover, when restoring the displayed picture back to the normal usage state (i.e., 0xc2x0-direction), the operation of the power saving controlling unit is also restored back to its original working condition.